On May 11, the French government announced it would ban speedcam warning systems (see here). The decision is part of a set of measures intended to decrease the number of accidents on French roads.
Without debating the pros and cons of such a decision, we think banning speedcam warning systems is likely to fail on a legal standpoint.
The exchange of information is indeed protected by the French Constitution and the European Convention on Human Rights. Passing a law that restrict freedom of expression or freedom to receive and transmit information is therefore likely to fail.
There are certainly other ways to prevent drivers from speeding up, than restricting basic human rights: increase the number of speedcams, move mobile speedcam faster from one location to the other, install "radars tronçons" (radar which calculates an average speed between 2 measurement points), use unmarked cars and motorcycles. This is the Sword versus Shield debate !